Vehicle surroundings monitoring apparatus and traveling control system incorporating the apparatus

A vehicle surroundings monitoring apparatus inputs images taken by a stereoscopic camera, vehicle speeds, steering wheel rotation angles, yaw rates and ON-OFF signals of a turn signal switch. An own traveling path C is calculated from an own traveling path A obtained from lane markers and side walls and an own traveling path B obtained from yaw rates of the own vehicle. Further, a new own traveling path E is calculated from the own traveling path C and a trace of a preceding vehicle, in case where there is no possibility of evacuation of the preceding vehicle and the turn signal switch is turned off and the absolute value of the steering wheel rotation angle is smaller than a specified value and a present own traveling path is calculated from the own traveling path E and the previous own traveling path. In other cases, the present own traveling path is calculated from the own traveling path C and the previous own traveling path.